Airborne immunization against tuberculosis

Inhalation of very small numbers of living attenuated (BCG) organisms and their multiplication in guinea pigs results in the development of acquired resistance against subsequent airborne infection with virulent tubercle bacilli. Different strains of BCG have differing capacities to immunize by this means.     

THYMUS: ITS LIMITED ROLE IN THE RECOVERY OF HOMOGRAFT RESPONSE IN IRRADIATED MICE

Adult mice subjected to thymectomy or sham thymectomy received lethal irradiation and subsequent protective infusion of syngeneic bone marrow. Thirty days later they received allogeneic and xenogeneic skin grafts. Donors of the xenogeneic grafts were rats. The thymectomized mice rejected the grafts of rat skin only slightly later than the controls did; in contrast, the time of retention of allogeneic grafts was significantly longer in the thymectomized mice.     

Homograft tolerance in mice: use of urethan and sublethal irradiation

Adult mice [CBA/J (H-2(k))], which received either a single sublethal dose of x-radiation (500 rad) or urethan plus 500 rad, were given intravenous injections of C3H/HeJ (H-2(k)) spleen or bone marrow cells (18 to 42 x 10(6) cells per mouse) or both, for 3 days. C3H/HeJ tail-skin homografts were retained (over 130 days) by these mice, whereas BALB/cJ (H-2(d)) homografts all were rejected within 33 days. Similarly irradiated or urethan-treated controls (or controls treated with a combination of both), which did not receive C3H cells, rejected both homografts. Specific homograft tolerance is induced in adult mice by this procedure.     

A survey of public attitudes towards barking dogs in New Zealand

AIMS: To investigate public attitudes towards barking dogs in New Zealand in order to quantify the extent to which people perceive barking dogs to be a problem, to compare tolerance of barking with that of other common suburban noises, to assess the level of public understanding about the function of barking, to determine risk factors for intolerance of barking and to assess knowledge of possible strategies for the investigation and management of problem barking.

METHODS: A 12-page questionnaire was sent to 2,000 people throughout New Zealand randomly selected from the electoral roll. Risk factors for being bothered by barking were examined using logistic regression analysis.

RESULTS: A total of 1,750 questionnaires were successfully delivered; of these, 727 (42%) were returned. Among respondents, 356/727 (49.0%) indicated that frequent barking during the day would bother them while 545/727 (75.0%) would be bothered by barking at night. Barking and howling were ranked above other suburban noises as a cause of annoyance. Risk factors for being bothered by daytime barking were not being home during the day, not owning a dog, and considering a dog bite to be a serious health risk. Risk factors for being bothered by night-time barking were not being home during the day, marital status, considering dog bites to pose a serious health risk, and having been frightened by a dog. Overall, 510/699 (73%) respondents understood that barking was a form of communication.

Action likely to be taken by 666 respondents hearing frequent barking included notifying and offering to help the owner (119; 17.8%), complaining to the owner (127; 19.1%) or the authorities (121; 18.2%), or doing nothing (299; 48%). Possible responses by 211 dog owners if they had a barking dog included seeking help from dog trainers (59; 28%) or behaviourists (54; 26%), buying an anti-barking device (33; 15%) or getting rid of the dog (20; 10%).

CONCLUSIONS: Barking was considered to be potentially disturbing by respondents to this survey. Attitudes towards barking were most influenced by age, dog ownership, past experience with dogs and attitude towards dog bites. Public understanding of the possible reasons for barking and appropriate methods of managing the behaviour when it becomes a problem could be improved by better education and the provision of information through veterinary clinics and social media.     

TWO METHODS FOR QUANTITATIVE DESCRIPTION OF SOIL PARTICLE SHAPE

It was required to be able to measure the shapes of soil particles in order that the influence of shape on soil mechanical properties could be investigated. Two methods were developed, both of which can be applied to particle cross-sections or outlines. The first is a shape function which compares chord lengths with arc lengths around the particle outlines. The second method involves taking discrete Fourier transforms of the normalized curvatures of the outlines, and the production of curvature spectra. Both methods are illustrated with the use of the same data. The data were for three sizes of particle from a sandy soil. Both methods illustrate the greater asphericity or angularity of the smaller particles, which is consistent with the Griffith theory of comminution. Change in shape with particle size may be useful for classifying soils according to their methods of formation.